JP2004275504A - Automatic alignment device for ophthalmologic examination apparatus and ophthalmologic examination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique improving the accuracy of the measurement, reproducibility, reliability and operability by improving the accuracy of an optical measuring system relative to the eye to be examined by automatic positioning. <P>SOLUTION: This automatic alignment device is provided with an illumination light source 2 lighting an illumination light to the front eye part of the eye 1 to be examined from an optical axis 5; a CCD camera 25 receiving a reflected light on the optical axis 5 reflected from the illumination light source 20 to the front eye part; a peculiar value output means providing numerical value data prescribedly weighted according to the distance from a position determination point where the alignment is completed in a receiving position of the reflected light in a light receiving surface perpendicular to the optical axis 5; a calculating means adding and averaging the numerical value data of the eigenvalue output means based on the reflected light receiving position signal of the CCD camera 25; and a movement control means automatically moving the optical measuring system 2 so as to accord the light receiving position with the position determination point while adjusting the moving speed according to the prescribed weighting as the light receiving position approaches to the position determination point based on the output signal of the calculation means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ophthalmic examination apparatus, and more particularly to an ophthalmic examination apparatus that requires alignment control of a measurement optical system with respect to an eye to be examined.
[0002]
[Prior art]
Conventionally, many ophthalmic examination apparatuses require alignment (alignment or centering) between an eye to be inspected and an apparatus measurement system. As a system for performing this type of alignment, many systems are known in which a determination function and a position control function relating to an alignment state are incorporated in the apparatus itself.
[0003]
For example, Patent Literature 1 discloses an intraocular pressure measurement device that measures the intraocular pressure of an eye to be inspected, a position adjustment device that controls movement of a position of a measurement system based on a detection unit that detects a displacement direction of a reflected image on a corneal surface. Is disclosed.
[0004]
Patent Literature 2 discloses an intraocular pressure measuring device that measures the intraocular pressure of an eye to be inspected, in which an movable unit of a measurement system is moved three-dimensionally and controlled based on a unit that detects an alignment state using corneal reflected light. A manometer is disclosed.
[0005]
Patent Literature 3 discloses, in an ophthalmologic measurement apparatus that measures protein concentration in an anterior chamber, a device that processes and outputs an output signal from a photoelectric conversion element to determine and display the suitability of an alignment state between a measurement system and an eye to be examined. Have been.
[0006]
Patent Literature 4 discloses an apparatus for driving a main body of a corneal cell imaging apparatus such that a measurement system is aligned with a cornea of an eye to be examined via an XY alignment detection circuit based on an output signal of a detection sensor. ing.
[0007]
Patent Literature 5 discloses an eyeball microscope apparatus that includes a unit that displays an alignment circle on an anterior ocular segment image and that performs alignment of a microscope optical axis with respect to an eye to be examined using a reflected light point from an eye sphere. Have been.
[0008]
Patent Literature 6 discloses an eyeball imaging apparatus for observing corneal endothelial cells, in which gate means that opens corresponding to a predetermined section of a television image and movement and adjustment of the entire apparatus based on processing of a corneal reflection signal through the gate means. Thus, an apparatus for automatically positioning a subject's eye with respect to an eyeball is disclosed.
[0009]
Patent Literature 7 discloses a corneal imaging apparatus that drives a moving mechanism via an XY direction position detection circuit based on a signal output of a TV camera, and positions a corneal endothelial cell imaging system with respect to an eye to be examined. .
[0010]
[Patent Document 1]
JP-A-62-19150
[Patent Document 2]
JP-A-01-300929
[Patent Document 3]
JP-A-03-264044
[Patent Document 4]
Japanese Patent Publication No. 07-112255
[Patent Document 5]
JP 06-160727 A
[Patent Document 6]
Japanese Patent No. 2607216
[Patent Document 7]
Japanese Patent No. 2608852
[0011]
[Problems to be solved by the invention]
However, in the device disclosed in Patent Literature 3, even though the suitability of the alignment state can be determined by a machine, the positioning of the device must be manually performed by an examiner (medical staff such as a doctor, a nurse, or an inspector). For this reason, there is a problem that the mechanical operation is troublesome, and there is a problem that the measured value is varied due to the skill of the examiner in the manual positioning operation, and it is difficult to obtain a good image in a short time in an image observation application. There is.
[0012]
On the other hand, in the devices disclosed in Patent Documents 1, 2, 4, 5, 6, and 7, since the positioning of the machine with respect to the eye to be inspected is performed automatically, there is no trouble associated with manual operation, and the operability and measurement accuracy of the machine are eliminated. Is expected, but there are the following problems.
[0013]
That is, since all the devices move and adjust the measurement system main body having a volume and a weight by simple mechanical control in the XY directions, it is difficult to accurately control the positioning of the measurement system with respect to the eyeball.
[0014]
In particular, in the device disclosed in Patent Document 6, in order to move and adjust the measurement system, a spot light source modulated at a constant frequency and synchronous detection are used, and a gate means that opens corresponding to a predetermined section of a television image is used. A specific circuit method or the like for performing signal processing is presented.
[0015]
However, in the device of Patent Document 6, since the control of the XY moving mechanism still depends on simple direction control, it is difficult to stop the optical system body accurately when the eyeball and the optical axis of the device match. Depending on the weight of the moving part, the hunting phenomenon may occur during the control by repeatedly passing the stop position.
[0016]
On the other hand, in the devices disclosed in Patent Documents 1, 2, 4, 5, and 7, a motor control changeover switch (Patent Document 1), a light receiving element for alignment (Patent Document 2), and an XY alignment detection circuit (Patent Document 4) ), A flicker detection device (Patent Document 5) or an XY direction position detection circuit (Patent Document 7), but only discloses simple automatic directional control in the XY directions, and measures an eyeball. No specific control method for improving the positioning accuracy of the system is disclosed.
[0017]
For example, as an ophthalmic examination apparatus developed in recent years, there is an ophthalmic examination apparatus (refer to Patent Document 3) also referred to as a laser flare meter for measuring a protein concentration in an anterior chamber of a subject's eye. This type of device requires a unique optical configuration in which a laser beam is projected from the oblique direction to the anterior chamber of the eye to be detected and weak scattered light is detected from the oblique direction.
In addition, since it is necessary to avoid unnecessary stray light from the cornea and the iris, the position of the eye to be inspected and the device must be very accurately adjusted at the time of measurement. Therefore, even if the conventional direction control mechanism is used as it is, it has been difficult to improve the accuracy and stability of the measurement by the conventional automatic positioning to a sufficiently satisfactory degree.
[0018]
The present invention has been made in view of the above prior art, and aims to improve the accuracy of automatic positioning of the measurement optical system with respect to the subject's eye, thereby improving measurement accuracy, reproducibility, reliability, and operability. It is to provide a technology that can be improved.
[0019]
[Means for Solving the Problems]
In the present invention, the position of the light receiving position is determined by a predetermined weighting according to a distance from a position determination point at which the predetermined alignment is completed corresponding to the light receiving position of the light receiving unit that receives the reflected light from the anterior segment of the subject's eye. The measurement optical system is automatically moved so as to match the determined point. The weighting at this time is reflected in the moving speed of the measuring optical system to the position determining point of the light receiving position, and the moving speed of the measuring optical system is adjusted as the light receiving position approaches the position determining point, and is preferably controlled to be slower. Is performed.
[0020]
Therefore, in the vicinity of the position determination point, the moving speed of the measuring optical system is slow, and the light receiving position moves slowly and approaches, so that the light receiving position can be positioned with high accuracy with respect to the position determining point. On the other hand, if the light receiving position is far from the position determination point, the moving speed of the measuring optical system is high, and the light receiving position moves at a high speed toward the position determination point, so that the time until positioning can be shortened. This can reduce the burden on the subject who is staring at.
[0021]
Furthermore, even if eye movement occurs and the anterior segment of the subject's eye moves rapidly, the positioning for matching the light receiving position to the position determination point is automatically controlled in accordance with the movement. The alignment is also maintained well.
[0022]
In order to achieve the above object, in the automatic alignment device for an ophthalmic examination device of the present invention,
An illumination light source that irradiates illumination light to the anterior segment of the subject's eye from the front of the subject's eye,
A light-receiving unit that receives the reflected light reflected by the anterior segment of the illumination light,
For the light receiving position of the reflected light on the light receiving surface perpendicular to the optical axis of the eyeball of the eye to be examined, eigenvalue output means for providing numerical data given a predetermined weighting according to a distance from a position determination point at which alignment is completed,
A calculating means for averaging numerical data of the eigenvalue output means based on a light receiving position signal of the reflected light of the light receiving unit,
As the light receiving position approaches the position determining point based on the output signal of the calculating means, the measuring optical system adjusts the moving speed in accordance with the predetermined weighting so that the light receiving position matches the position determining point. Movement control means for automatically moving.
[0023]
In this configuration, the movement control means performs the movement of the measuring optical system by adjusting the moving speed as the light receiving position approaches the position determination point, preferably while slowing the movement, by the predetermined weighting of the numerical data provided by the eigenvalue output means. Therefore, the positioning accuracy for matching the light receiving position to the position determination point is sufficiently improved, and the accuracy, reliability, and operability of the measurement can be improved.
[0024]
In addition, when the light receiving position is far from the position determination point, the movement control means can move the measurement optical system at a high speed, thereby shortening the time until positioning, and the subject staring at one point. Burden can be reduced.
[0025]
In addition, when the light receiving position substantially coincides with the position determination point by the movement control means, the measurement optical system is automatically set in the optical axis direction so as to determine a predetermined position in the optical axis direction of the eyeball of the subject's eye. It is preferable to include an optical axis direction movement control means that moves with respect to.
[0026]
In this configuration, after the alignment of the eye to be inspected in the vertical plane with the optical axis of the eye is completed, the alignment of the eye to be inspected is adjusted in the optical axis direction of the eye. The three-dimensional alignment can be completed by moving the measuring optical system, and the accuracy can be improved in a short time until positioning.
[0027]
In the ophthalmic examination apparatus of the present invention,
An auto-alignment device for the above ophthalmic examination device,
A measurement optical system for performing measurement after the alignment is determined by the auto-alignment device for the ophthalmic examination apparatus.
[0028]
With this configuration, the positioning accuracy for matching the light receiving position to the position determination point is sufficiently improved, and the accuracy, reproducibility, reliability, and operability of the measurement can be improved.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. An embodiment will be described with reference to FIGS.
[0030]
FIG. 1 is a schematic configuration diagram of a laser flare meter (hereinafter, referred to as LFM) according to the present embodiment. In the present embodiment, description will be given with LFM as an example of an ophthalmic examination apparatus.
[0031]
FIG. 1 shows a subject's eye 1, which is an eyeball of a subject, and an LFM measurement optical system 2 is arranged to face the subject's eye 1.
[0032]
The measuring optical system 2 is roughly composed of an optical path divided into a light projecting system optical axis 3, a light receiving system optical axis 4, and an optical axis (center axis) 5 of an LFM apparatus main body parallel to the eyeball optical axis of the eye 1 to be examined. ing.
[0033]
For example, the set angle of the center axis of the light projecting system optical axis 3 with respect to the optical axis 5 is set to 30 degrees. On the other hand, the set angle of the central axis of the light receiving system optical axis 4 with respect to the optical axis 5 is set to 40 degrees.
[0034]
Next, the light projection system of the LFM will be described. In the light projecting system, the laser light emitted from the laser light source 6 passes through the lens 7, the galvanometer mirror 8, the mirror 9, and the lens 10 along the light projecting system optical axis 3 in the anterior chamber of the subject's eye 1. It is projected on.
[0035]
The galvanometer mirror 8 is driven by the galvanometer 8M, and scans the laser beam finely and one-dimensionally in the anterior chamber.
[0036]
The scattered light from the protein existing in the anterior chamber of the eye 1 is detected along the light receiving system optical axis 4 by the photoelectric detector 14 such as a photomultiplier tube via the lenses 11 and 12 and the mask 13. A filter 15 corresponding to the wavelength of the laser light source 6 is disposed in front of the light receiving surface of the photoelectric detector 14.
[0037]
The output signal from the photoelectric detector 14 is supplied to a signal processing circuit 16 for flare measurement. In the flare measurement signal processing circuit 16, the protein concentration is calculated from the output signal of the scattered light, and the measurement result is displayed on the display device (liquid crystal monitor) 18 via the display control circuit 17.
[0038]
The display control circuit 17 also exchanges various control signals with an alignment signal processing circuit 19 described later.
[0039]
On the other hand, with respect to the optical configuration along the optical axis 5 of the central axis, the illumination light from the illumination light source (infrared LED) 20 is transmitted through the lens 21, the split mirror (half mirror) 22, and the lens 23 to the eye 1. Irradiated to the anterior segment.
[0040]
Incidentally, in order to determine the line of sight of the subject's eye 1, a fixation target (not shown) for the subject's eye 1 to fixate can be provided near the illumination light source 20 or the lens 21.
[0041]
An anterior segment image of the subject's eye 1 based on the reflected and diffused light from the illumination light source 20 passes through a lens 23 and a split mirror 22 on the optical axis 5, and then a CCD camera 25 that constitutes a light receiving unit by a lens 24. Is imaged on the light receiving surface of. On the front surface of the light receiving surface of the CCD camera 25, an infrared filter 26 corresponding to the wavelength of the infrared LED of the illumination light source 20 is arranged in order to reduce the influence of disturbance light.
[0042]
Further, light directly reflected from the cornea of the eye 1 to be inspected by the laser light source 6 is detected by the auxiliary optical system, and therefore, a detection angle symmetrical with respect to the optical axis 3 of the light projecting system (in this embodiment, with respect to the optical axis 5). The optical axis 3S is set at 30 degrees. That is, the reflected light from the cornea of the laser light source 6 is guided through the lens 27 along the optical axis 3S, and is detected by the photodiode 28. A filter 29 corresponding to the wavelength of the laser light source 6 is arranged in front of the light receiving surface of the photodiode 28.
[0043]
The photodiode 28 is constituted by a two-division type photodiode or the like, and determines the distance (Z-axis direction) between the vertex of the cornea of the eye 1 and the measuring optical system 2 from the ratio of the amount of corneal reflection incident on the light receiving surface. This is for determining.
[0044]
Here, the photodiode 28 and the photoelectric detector 14 detect the reflected light or the scattered light of the laser light source 6, respectively, but the respective photometric parts are delicate such that they are located on the corneal surface of the subject's eye 1 and in the anterior chamber. Optically set with a difference in observation direction.
[0045]
By the way, in the LFM measurement, the laser beam from the laser light source 6 needs to be constantly applied to a predetermined search area in the anterior chamber of the subject's eye 1, and a displacement occurs between the subject's eye 1 and the measurement system. Then, unnecessary stray light components such as corneal reflection and iris reflection are mixed into the detection signal, causing a measurement error. Therefore, conventionally, the LFM measurement operation has been a very delicate and difficult procedure for both the examiner and the subject.
[0046]
In order to solve this problem, the LFM according to the present embodiment employs position control of the measurement optical system 2 using the output signal of the CCD camera 25 and the output signal of the photodiode 28 (auto-alignment device). I have.
[0047]
That is, the output signals from the CCD camera 25 and the photodiode 28 are input to the alignment signal processing circuit 19, where an operation for controlling the position of the measuring optical system 2 is performed, and the operation result is output to the motor control system. And used for automatic positioning.
[0048]
FIG. 2 is a block diagram showing in more detail the inside of the alignment signal processing circuit 19 for automatically controlling the position of the measuring optical system 2.
[0049]
The video signal output from the CCD camera 25 is separated into synchronization signals by a synchronization separation circuit 30, and the output is used for synchronization control of a display circuit system and other circuits.
[0050]
On the other hand, the video signal from the CCD camera 25 is input to the A / D conversion circuits 31X and 31Y, and after being converted into digital data, signal processing is performed.
[0051]
In FIG. 2, two similar circuit types are provided after the A / D conversion circuits 31X and 31Y, and these are signal signals corresponding to the X direction (horizontal direction) and the Y direction (vertical direction) of the video signal. This is for performing processing, and is referred to by reference numerals X and Y, respectively.
[0052]
The outputs of the A / D conversion circuits 31X and 31Y are compared with the data of the reference value generation circuits 33X and 33Y via the comparison circuits 32X and 32Y, and supplied to the averaging circuits 34X and 34Y.
[0053]
The averaging circuits 34X and 34Y add and average the output data of the memory circuits (ROM) 36X and 36Y controlled by the address counters 35X and 35Y in the data area output from the comparison circuits 32X and 32Y. The location of the captured anterior eye image (light receiving position) of the subject's eye 1 in the display image area is quantified according to a predetermined weighting from a position determination point (image center) preset in the display image area. This is an arithmetic means.
[0054]
The address counters 35X and 35Y and the ROMs 36X and 36Y form eigenvalue output means, and are replaced by a CPU (microprocessor) or a PLD (programmable logic device) including the averaging circuits 34X and 34Y. Can also be designed.
[0055]
Numerical data output from the averaging circuits 34X and 34Y determine the positive / negative direction via the polarity determining circuits 37X and 37Y, and control the motor driving circuits 38X and 38Y to adjust the position of the measuring optical system 2. Drive motors 39X and 39Y.
[0056]
Further, the outputs of the averaging circuits 34X and 34Y are converted into analog quantities via D / A conversion circuits 40X and 40Y, and are passed through PWM circuits (pulse width modulation circuits) 41X and 41Y. 38Y is controlled. By performing the PWM control based on the output data of the averaging circuits 34X and 34Y, the driving power of the motor can be adjusted according to the position of the anterior segment image of the subject's eye 1 in the display image area.
[0057]
Further, the output signals of the D / A conversion circuits 40X and 40Y are supplied to an XY area determination circuit 42, where it is determined whether the anterior eye image of the subject's eye 1 exists within a predetermined range in the display image, and the position is determined. The control in the Z-axis direction (the direction of the optical axis 5 as the central axis) is performed under the condition of approaching (substantially coincident) with the image center which is a point.
[0058]
That is, the output signal from the split-type photodiode 28 is converted into position data in the Z-direction by the arithmetic circuit 43 by calculating the ratio of the amount of detected light for the two-divided sensor.
[0059]
Subsequently, the Z-axis control determining circuit 44 determines whether to perform the drive control in the Z-direction in consideration of the output result of the XY area determining circuit 42, and determines whether the Z-axis movement adjusting motor 46 via the motor driving circuit 45. Perform control.
[0060]
The effect of this type of three-dimensional position control due to the eyeball fixation micro-movement of the subject's eye 1 frequently appears at high speed in the XY axis direction, and depending on the type of measurement system, the tracking correction in the XY axis direction rather than the Z axis direction. Was difficult. Therefore, in the present embodiment, circuit techniques such as eigenvalue output means and PWM control are employed in the XY-axis control in a complicated and effective manner, while the control system in the Z-axis direction is realized as a simpler configuration. I have.
[0061]
FIG. 3 is a diagram showing numerical data provided by the eigenvalue output means. In FIG. 3, reference numeral 47 corresponds to the outer frame of the display image area output by the CCD camera 25. It is assumed that an X-axis and a Y-axis are virtually set in the outer frame 47 with reference to the image center, which is a position determination point.
[0062]
FIG. 3A schematically shows numerical data of weighting for control in the X-axis (horizontal) direction, and FIG. 3B schematically shows numerical data of weighting for control in the Y-axis (vertical) direction. I have.
[0063]
In FIG. 3, numerical data are set as eigenvalues in three stages concentrically outward from the center of the image, which is the position determination point, with weights of ± 1 to ± 3. It is set and provided in advance as numerical data having a predetermined weight.
[0064]
These numerical data are individually averaged in the local region of the image corresponding to the anterior segment image (corneal image) of the subject's eye 1 in the X direction and the Y direction, respectively, so that the directions of the motor driving circuits 38X and 38Y are changed. It can be used for both setting and power setting.
[0065]
Specifically, in the direction setting, the direction is determined by weighting “+” and “−”, and in both the XY directions, the measuring optical system 2 moves in the negative XY direction with the weighting of “−”. It moves and moves in the positive direction of the XY direction with the weighting of “+”. In the power setting, the power is determined by weighting values of 1 to 3, and as the distance from the image center increases, the weighting value increases. Therefore, in the vicinity of the center of the image, the power is “1”, which is small, the motor driving speed is low, and the measuring optical system 2 moves slowly. On the other hand, when the distance from the center of the image increases, the power increases to “3”, the motor driving speed increases, and the measuring optical system 2 moves at high speed.
[0066]
FIG. 4 is an explanatory diagram schematically illustrating a state in which an anterior eye image of the subject's eye 1 captured by the CCD camera 25 moves by the motor drive control of FIG.
[0067]
The anterior ocular segment image 48 of the subject's eye 1 exists in the upper right (A, B) = (+ 3, +3) region of the image in FIG. 4A, and straddles the Y axis in FIG. 4B. In FIG. 4 (c), the upper left position (A, B) = (− 2, +2). In FIG. 4 (c), the position approaches (A, B) = (− 1, +1). In d), the moving speed is reduced and the image converges on the image center of (A, B) = (± 0, ± 0), and the center of the cornea of the eye 1 to be examined is positioned.
[0068]
That is, the locus of positioning of the cornea center of the subject's eye 1 in FIG. 4 draws a gradually decreasing wave while swinging across the X-axis or the Y-axis by the weighting in FIG. 3, and converges to the image center. Become.
[0069]
These image changes shown in FIGS. 4A to 4D are performed within a short time by driving the position adjustment motors in the X direction and the Y direction. Is automatically controlled while being adjusted by the predetermined weighting shown in FIG.
[0070]
Therefore, when the anterior ocular segment image 48 matches the center of the image, the motor finally comes close to the center of the image at a slow speed, so that the motor can be stopped very accurately without going over the center.
[0071]
In addition, in the case of FIGS. 3 and 4, if either one of the XY directions is far, the power for controlling the distant places in the XY directions becomes large, so that the alignment between the apparatus and the subject's eye 1 is greatly deviated. In this case, the moving speed of the measurement optical system 2 can be increased. Therefore, since the anterior ocular segment image 48 is automatically moved in accordance with the weight so as to immediately position the anterior ocular segment image 48 at the center of the image, it is possible to follow the measurement optical system 2 quickly and accurately. Can be positioned extremely accurately in the search area in the eyeball.
[0072]
In FIGS. 3 and 4, numerical data of ± 1 to ± 3 are schematically shown assuming simple settings defined by concentric weighting ranges. Needless to say, more complicated numerical data is set as an eigenvalue in accordance with the weight balance and the driving characteristics of the motor, and is used for the calculation.
[0073]
For example, as another example, control by weighting as shown in FIGS. 5 and 6 is also possible.
[0074]
FIG. 5A schematically shows numerical data of weighting for control in the X-axis (horizontal) direction, and FIG. 5B schematically shows numerical data of weighting for control in the Y-axis (vertical) direction. I have.
[0075]
In FIG. 5, in the X-axis direction, numerical data are set as eigenvalues in six steps toward the X-axis direction and weighted from −3 to +3, and in the Y-axis direction, six values are set in the Y-axis direction. Numerical data is set as eigenvalues with weights of -3 to +3 at the stage. Thus, the data is preset and provided as numerical data having a predetermined weight in the display image area. Also in this case, the power for driving the motor is small near the center of the image, and the power for driving the motor increases when the distance from the center of the image is increased.
[0076]
FIG. 6 is an explanatory diagram schematically illustrating a state in which the anterior eye image of the subject's eye 1 captured by the CCD camera 25 moves by the motor drive control of FIG.
[0077]
The anterior ocular segment image 48 of the subject's eye 1 first exists in the upper right (A, B) = (+ 3, +3) region of the image in FIG. 6A, and in the following upper right (A) in FIG. 6B. , B) = (+ 2, +2), approaching the center of the image in FIG. 6C, and moving to a position of (A, B) = (+ 1, +1). Finally, in FIG. The image slowly converges to the image center of (A, B) = (± 0, ± 0), and the corneal center of the subject's eye 1 is positioned.
[0078]
That is, the locus of positioning of the corneal center of the subject's eye 1 in FIG. 6 moves on a straight line connecting the corneal center and the image center and converges to the image center by weighting in FIG.
[0079]
Therefore, in the case of FIG. 5 and FIG. 6, since the image moves toward the image center by linear movement to the image center, the movement of the shortest distance is sufficient, and the time required for the movement can be reduced.
[0080]
Next, a mechanism for controlling the position of the measurement optical system 2 will be described with reference to FIG. FIG. 7 is a schematic view showing a position control mechanism in the XYZ directions.
[0081]
The subject supports his or her head via the chin rest 49 and the forehead pad 50 attached to the apparatus, so that the subject's eye 1 faces the measuring optical system 2. The moving table 51 of the apparatus is configured on a gantry section 52, and the measuring optical system 2 can be roughly moved by a joystick 53.
[0082]
On the other hand, the positioning and fine adjustment of the measuring optical system 2 with respect to the subject's eye 1 are performed by moving the measuring optical system 2 in the three-dimensional directions of the XYZ axes by the above-described automatic positioning control via the rails 54X, 54Y and 54Z. Done by
[0083]
The operations in these three directions are performed by the motors 39X, 39Y, 46 and the gears 55X, 55Y, 55Z connected thereto, respectively. The control of the motors is performed through a signal processing circuit as shown in FIG. Even if there is eye movement, highly accurate automatic tracking is always achieved.
[0084]
【The invention's effect】
As described above, the present invention can improve the accuracy when performing automatic positioning of the measurement optical system with respect to the eye to be inspected, and can further improve the measurement accuracy, reproducibility, reliability, and operability as an inspection device. .
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a laser flare meter according to an embodiment.
FIG. 2 is a block diagram illustrating the inside of an alignment signal processing circuit according to the embodiment;
FIG. 3 is a diagram showing numerical data provided by an eigenvalue output unit according to the embodiment.
FIG. 4 is an explanatory diagram schematically illustrating a state in which an anterior segment image of the subject's eye according to the embodiment moves by the motor drive control of FIG. 3;
FIG. 5 is a diagram showing numerical data provided by eigenvalue output means according to another example of the embodiment.
6 is an explanatory diagram schematically illustrating a state in which an anterior eye image of an eye to be examined moves according to the motor drive control of FIG. 5 according to another example of the embodiment.
FIG. 7 is a schematic diagram showing a position control mechanism in the XYZ directions according to the embodiment.
[Explanation of symbols]
1 Eye to be examined
2 Measurement optical system
3 Projection system optical axis
3S optical axis
4 Optical axis of light receiving system
5 Optical axis
6 Laser light source
7 Lens
8 Galvanometer mirror
8M galvanometer
9 Mirror
10 lenses
11,12 lens
13 Mask
14 Photoelectric detector
15 Filter
16 Flare measurement signal processing circuit
17 Display control circuit
18 Display device
19. Alignment signal processing circuit
20 Illumination light source
21 lenses
22 split mirror
23 lenses
24 lenses
25 CCD camera
26 Infrared filter
27 lenses
28 split type photodiode
29 Filter
30 Sync separation circuit
31X, 31Y A / D conversion circuit
32X, 32Y comparison circuit
33X, 33Y reference value generation circuit
34X, 34Y averaging circuit
35X, 35Y address counter
36X, 36Y ROM
37X, 37Y polarity judgment circuit
38X, 38Y motor drive circuit
39X, 39Y, 46 motor
40X, 40Y D / A conversion circuit
42 XY area determination circuit
43 Arithmetic circuit
44 Z axis control judgment circuit
45 Motor drive circuit
47 Outer frame
48 Anterior eye image
49 chin rest
50 forehead
51 Mobile platform
52 Stand
53 Joystick
54X, 54Y, 54Z rails
55X, 55Y, 55Z Gear

Claims (3)

An illumination light source that irradiates illumination light to the anterior segment of the subject's eye from the front of the subject's eye,
A light-receiving unit that receives the reflected light reflected by the anterior segment of the illumination light,
For the light receiving position of the reflected light on the light receiving surface perpendicular to the optical axis of the eyeball of the eye to be examined, eigenvalue output means for providing numerical data given a predetermined weighting according to a distance from a position determination point at which alignment is completed,
A calculating means for averaging numerical data of the eigenvalue output means based on a light receiving position signal of the reflected light of the light receiving unit,
As the light receiving position approaches the position determining point based on the output signal of the calculating means, the measuring optical system adjusts the moving speed in accordance with the predetermined weighting so that the light receiving position matches the position determining point. An automatic alignment apparatus for an ophthalmic examination apparatus, comprising: a movement control unit that automatically moves. When the light receiving position substantially coincides with the position determination point by the movement control means, the measurement optical system automatically performs a predetermined position determination in the eyeball optical axis direction of the subject's eye with respect to the optical axis direction. The auto-alignment apparatus for an ophthalmic examination apparatus according to claim 1, further comprising an optical axis direction movement control unit that moves. An auto alignment apparatus for an ophthalmic examination apparatus according to claim 1 or 2,
An ophthalmologic examination apparatus comprising: a measurement optical system that performs measurement after alignment is determined by the autoalignment apparatus for the ophthalmic examination apparatus.

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